Influence of the oxygen concentration on the morphology
and size of ZnO nanostructures have been
reported by a few authors using thermal evaporation
technique. Haung et al.[28] obtained different
kinds of nanocombs by controlling the Zn and oxygen
partial pressure during the growth. Whereas,
Fu et al.[29] found different ZnO morphologies such
as nano-cones, nanoneedles and nanoparticles when
the oxygen concentration was varied as 5×10−6,
10×10−6 and 250×10−6, respectively.